I put a fairly low emphasis on sharpening in the field. For the most part I don't feel it's necessary, nor do I feel it's possible to do a good job sharpening that way. My method involved water stones in a progression up to pretty high grits. Or a belt sander for some types of knives. For the most part high end supersteels will hold an edge sufficiently long that resharpening in the field is unnecessary (at least for my purposes). If you badly chipped the edge it would be a real b!tch to fix that out in the sticks, anyways. Having a second knife is perhaps a better use of the weight and space than a full sharpening rig would be. All I generally carry is a ceramic hone or small strop.